Fine grain photographic developer



10 on development.

Patented Apr. 5, 1938 I UN'TED ST AT NT -OFFIC rum an nsrno'roaaarmo navanoraa v Paul w. vmum. Rochester, N. r, assignor," by aslignlnen mesne ts, to. Eastman Kodak Company, Jersey City, N. 1., a corporation of New Jersey I No Drawing. Application November 2, 19 35, Serial No. 48.049 j j h x 4' Claims. sis-as) v V This invention relates to photographic devel- Tertiary amine salts opers and more particularly to developers which 1 produce a fine-grain image. cmr-N-nci 'iriethylamine hydrochloride It is desirable in developing photographic film Cm which are to be used for producing an image by c OH projection either for cinematographic purposes a or for still pictures, to have a. fine-grain image (CIE4OH)N-HCI 'lriethanolamine hydrochloride on the negative. Numerous methods have been (mm'om suggested for obtaining these fine-grain images Among these methods are the use of a developing agent which produces a finegrain image, such as paraphenylenediamine, and

the addition of special agents which slow down the speed of development. Many of these methods have the disadvantage of causing fog on development or require the use of poisonous or otherwise undesirable developing agents. In prior Patent Number 2,053,516 granted September 8,

1936 to J. I. Crabtree and myself, the use of ammonium chloride in metol-hydroquinone developers was described. These developers produce a fine-grain image but they possess the undesirable feature of loss of ammonia on aeration.

The principal object of the present invention is to provide a non-fogging photographic developer which is effective in reducing graininess of the image. A further object is to provide a fine-grain photographic developer which is stable toward aeration.

These objects are accomplished in the present invention by adding certain aliphatic amine salts. namely, acid-reacting, aliphatic substituted ammonium salts, to the developer.

In producing a fine grain photographic devel-- oper according to my invention, I add to an ordinary photographic developing solution a salt of a primary, secondary, or tertiary aliphatic amine such as an alkylamine or an alkanolamine or alkylenediamine. I prefer to use thehydrochio- Thefollowing developing solutions containing amine'salts, which are given by way of example only, may be used according to my invention.

Example 1 p-Methylaminophenol sulfate grams 5 Hydroquinone do 2.5 Sodium suiiite (desiccated) do 80 Ethanolamine hydrochloride -do '15 Sodium metaborate do; 6 Potassium bromide do.... 1 Water to l iiter 1 '1 Example 2 p-Me'thyiaminophenol sulfate grams 2 Hydroquihone; ..do 5 Sodium sulfite desiccated); do l00 Ethanolamine hydrochloride do.. Sodium metaborate do 2 Water to liter-.. 1

- Examples p-Methylaminophenol sulfate grams 5 Hydroquinone ..do 2.5 Sodium'sulflte (desiccated) do Ethylenediamine dihydrochloride' do 50 Sodium metaborate do- 6 Potassium bromide, ..do 1 Water to liter 1 Example 4 p-Methylaminophenol sulfate grams 2 Hydroquinone do 5 Sodium sulfite (desiccated) do Ethylenediamine dihydrochloride do 50 Sodium metaborate do 2 Water to 1113612. 1

Example 5 Amidoi (dlaminophenol hydrochloride) grams 2.5 Ethyienediamine dihydrochloride do 50 Sodium sulflte (desiccated): ..do 50 Potassium bromide do 0.25 Water to liter 1 Example 6 p-Aminophenol oxalate grams 2.5 Sodium sulflte (desiccated) do 50 Ethylenediamine hydrochloride do 50 Sodium metaborate do 10 Potassium bromide do--- 0.5 Water er" 1 The aliphatic amine salts used in the developing solutions according to my invention may be prepared by neutralizing an aqueous solu-' tlon of the desired amine with an acid and separating the pure amine salt by evaporation. The preparation of these compounds however, forms no part of my invention. An alternate procedure consists of forming the salt in the developing solution by adding to the developing solution equivalent amounts of the'amine and the acid.

1 While in a number of the above examples I have referred to developers in which the developing agent is paramethylaminophenol sulfate and hydroquinone', usually referred to as "M-Q, it is to be understood that developers may be prepared according to my invention in which other types of developing agents are used. For example, developers containing developing agents such as diaminophenol hydrochloride, paraminophenol oxalate, etc., may be used as fine grain developers upon addition of the aliphatic amine salts which I have disclosed. In addition to the aliphatic amine salts referred to above I may use salts of other aliphatic amines, for example, salts of methyl, ethyl, propyl, or higher alkyl amines. I may also use salts of substituted alkyl amines such as benzylamine. Other compounds which may be used according to my invention are cycloalkylamines such as cyclohexylamine and unsaturated allphatic amines as propenylamines. In the case of the alkylene diamine I may use either the monoor the dihydrochloride.

The compounds which I have described do not function in equal degrees as fine-grain producing agents but all of them will reduce the grain size of the developed iinage to some extent. I have found that in general the primary amines In using a photographic developer it is frequently necessary to agitate the developing solution. in order to secure uniformity of development. This agitation tends to bring the developing solution into contact with the air to a greater extent than if it were not agitated. It has also been proposed to blow air through the developer in order to secure agitation. For this reason it has been found that a fine grain developer containing ammonium chloride loses its activity quite rapidly as a result of loss of ammonia from the solution. When amine salts are used in place of ammonium chloride, the developer is morestable toward aeration and can be used for a longer time without being replenished.

What I desire to claim and secure by Letters Patent of the United States is:

.1. A fine-grain photographic. developer comprising a developing agent and a strong acid salt of ethylenediamine.

2. A fine-grained photographic developer comprising a developing agent and an ethylenediamine hydrochloride.

3. A fine-grain photographic developer comprising an M-Q developing agent and an ethylenedlamine' hydrochloride.

4. A fine-grain photographic developer comprising diaminophenol hydrochloride and ethylenediamine dihydrochloride.

PAUL W. VIT'I'UM. 

